Even if you can't fall asleep for a nap, just laying down and resting has benefits. Studies have found resting results in lowered blood pressure, which even some college kids have to worry about if they are genetically predisposed to high blood pressure.

The way this works is you drink a cup of coffee right before taking your 20-minute or half-hour nap, which is precisely how long caffeine takes to kick in. That way when you wake up, you're not only refreshed, but ready to go.